Automatic controlling switch mechanism



May 19, 1936. c. Y|:oMANs UTOMATIC CONTROLLING SWITCH MECHANISM 2 sheets-sheet 1 Filed Jan. 25, 1932 mmmmmmmmwwwmwmwmm\ww May 19, 1936. c. YEoMANs AUTOMATIC CONTROLLING SWITCH MECHANISM Filed Jan. 23, 1932 A 2 Sheets-SheXet 2 I. C/za/es oma/zsI wim, m, M Ma/@5,

Patented May 19, 1936 PATENT OFFICE AUTOMATIC CONTROLLING SWITCH MECHANISM Charles Yeomans, Chicago, Ill., assignor to Yeomans Brothers Comp poration of Delaware any, Chicago, Ill., a cor- Application January 23, 1932, Serial No. 588,305

10 Claims.

The invention relates to controlling switch mechanism and more particularly to change-over switches for effecting the alternate operation of two electrically operated units such, for example,

as the separate units of a duplex pump system.

In a duplex pump system, the separate electrically driven pumps are controlled by two float switches, one of which operates in advance of the other and, t-o alternate or change the sequence of operation of the pumps, a change-over switch has been used to interchange the connections between the float switches and the motors. The present invention more particularly seeks to provide an improved automatically operating, change-over switch for such systems, and in general, to provide an improved automatic periodically operating switch.

The invention consists in the features of improvement hereinafter set forth, illustrated in the accompanying drawings and more particularly pointed out in the appended claims.

In the drawings:

Fig. 1 is a view in elevation with parts shown in section of the improved double throw, changeover switch.

Fig. 2 is a similar view with some of the parts omitted and the switch shown in its other position.

Fig. 3 is a detail section on the line 3-3 of Fig. 1.

Fig. 4 is a plan view.

Fig. 5 is a diagram of the operating and controlling circuits of a duplex pump system.

As indicated in Fig. 5, two electric motors M1 and M2 operate separate pumps Pl and P2 and are cont-rolled by two float switches F1 and F2. 'I'he float switches are opened and closed by buttons I I mounted on the rods I I of a pair of floats I2 arranged within the receptacle or reservoir from which liquid is withdrawn by the pumps P1 and P2, and the buttons I I are so disposed on the float rods that switch F1 is closed in advance of the switch F2. These switches are interposed in controlling circuits for the motors and which circuits operate electro-magnetic starting contactors I3. Alternating current motors are indicated and are connected by the contactors and by manually operable knife switches I4 to the supply conductors I, 2 and 3, the contactors being interposed in conductors I', 2 and 3 leading from the knife switches.

A double pole, double-throw switch is interposed in the controlling circuits between the oat switches F1 and F2 and the contactors I3. This switch comprises four shiftable contacts, 4, 5, 6

and 1, each of which cooperates with a pair of fixed contacts. The movable contacts 4 and 5 of the change-over switch are connected to the contacts of the float switch F1 and the movable contacts 6 and 1 to those of the float switch F2. 5 The fixed contacts of the switches 4 and 6 are connected to the circuit conductor I when the knife switches I4 are closed. The lower xed contacts of the switch fingers 5 and 1 are connected to the coil of the starting contactor of 1o motor M1 and the upper xed contacts of the switch fingers are connected to the coil of the starter for the motor M2. The starter coils are also connected to the supply conductor 2 when the knife switches I4 are closed. With the mov- 15 able change-over switch contacts in the position shown in Fig. 5, motor M1 will be controlled by float switch F1, and motor M2 by the float switch F2. In the shifted position of the switch contacts 4, 5, 6 and 1, the circuit connections be- 20 tween the float switches and motors are interchanged, so that then motor M2 will be controlled by float switch F1, and motor M1 by the switch F2.

As shown in Figs. 1 and 2, the upper and lower 25 fixed contacts 9 and I0 of the change-over switch are mounted on and project upwardly from an insulating support I5 which is secured to the underside of a horizontal bar I6 forming part of a frame I1. 'Ihe movable contacts 4, 5, 6 and 1, 30 are in the form of flexible spring fingers and are secured to a supporting strip or piece I8 formed of insulating material and preferably fiber board. Lugs I9 on the frame bar I6 project upwardly through an opening 20 in the support I8 and the 35 latter is pivoted to these lugs so that it can oscillate and shift the contact lingers 4, 5, 6 and 'I into engagement with the upper and lower contacts. Preferably, the upper ends of the lugs are provided with V-shaped notches 2| which are en- 40 gaged by knife edges 22 formed at the side of the opening 20 in the support. A spring 23 connected at one end to the support and arranged within a cutaway portion or recess 24 therein maintains the support in position with the knife 45 edges 22 engaging the V-shaped seats 2|.

The opposite end of the spring is connected to a lug or arm 25 which depends from a shifter arm 26. The latter is connected at one end to the bifurcated portion 21 of the supporting frame 50 by a pivot pin 28. Its opposite end is provided with a weight 29 sc that it tends to descend into the position shown in Fig. 1. A pair of latches 30 and 3I are disposed between the lugs I9 on the frame and are connected thereto by pivot 55 pins 32. These latches extend through the opening 20 in the shiftable or oscillating support I8 and are arranged to engage the outer edge of this opening to hold the support in its two positions, latch 30 serving to hold the adjacent end of the support raised as shown in Fig. 1, and latch 3| serving to hold it in lowered position, as shown in Fig. 2. These latches are counterweighted so that they tend to move to their operating positions without the necessity of employing springs. The portion 33 of the shifter arm 26 above the latches is rearwardly offset, as shown in Fig. 4, so that the movement of this arm does not interfere with the latches. But the offset end of the depending lug 25 on the shifter arm is arranged to cooperate with lugs or offsets 34 and 35 on the latches to release the same. Also, the movement of the shifter arm changes the position of the spring 23 relative to the shiftable contact support I8.

A plunger 36 is arranged to engage the shifter arm 26 adjacent its pivoted end and preferably it contacts with a screw 31 adjustably threaded through the shifter arm and held in adjusted position by a lock nut 38. The plunger extends downwardly through a guide 39 and into a casing 40. The enlarged lower end of the plunger rests upon thermal wafers 4I below which is arranged a suitable heating resistance 42. A contact finger 43 mounted on the shiftable contact support I8 is arranged to cooperate with a lower fixed contact 44 to open and close the circuit of the heating resistance 42 which is connected to the supply conductors I and 2 when the knife switches I4 are closed.

When the switch shifter arm 26 is lowered as shown in Fig. l, the double-throw switch is locked in the position shown by the latch 30 and the circuit is closed through the heating coil of the thermostat. The thermal wafers gradually expand and, through the medium of the plunger 36, gradually lift the shifter arm 26. Since the plunger engages the latter adjacent its pivot, a slight movement of the plunger will effect a considerable throw of the shifter arm. As the latter moves upwardly it shifts the position of the spring from that shown in Fig. l toward that shown in Fig. 2, but the switch is not thrown until the shifter arm approaches the upper end of its movement. Then the lug 25 thereon engages the lug 34 and releases latch 30, so that the spring 23 quickly acts to shift the switch into the position shown in Fig. 2. This movement of the switch also opens the heating circuit of the thermostat so that the latter cools and the shifter arm is gradually lowered. As it is lowered the operating spring 23 is also moved downwardly, but the latch 3l holds the switch against movement until the shifter arm approaches the lower end of its movement. Then the lug 25 engages the lug 35 and releases the latch 3|, so that the spring 23 quickly shifts the switch back into the position shown in Fig. l.

The improved arrangement intermittently effects the quick throw of the change-over switch under control of a slow operating thermostat. In the preferred form, the movement of the throw of the switch is effected by a single spring and the movements of the switch shifter arm and latches are effected without employing springs. The arrangement also effects a good wiping contact between the fingers 4, 5, 6 and 'I and the fixed contacts.

Preferably the apparatus is enclosed within a casing 45, and preferably also means is provided for cooling the heating coil of the thermostat when its circuit is opened. For this purpose a small electric fan 46 is disposed within the casing and the contact finger 43 cooperates with its upper fixed contact 41 to open and close the circuit of the fan motor, as shown in the diagram. Fig. 5. Thus the fan and heating coil are alternately energized by the movement of the contact nger 43. The casing is provided with air inlet and outlet openings 48 and 49 and to further control the rate of cooling of the heater for the thermostat, one set of openings is preferably provided with an adjustable shutter 5U.

Preferably a manually operable switch 5I is interposed in the circuits of the thermostat heater and fan, as indicated in Fig. 5, so that the automatic operation of the change-over switch can be arrested if desired. Then the switch shifter arm 26 can be locked in position by a set screw 52.

Obviously changes may be made in the details set forth without departure from the scope of the invention as defined in the appended claims.

I claim as my invention:

1. In a circuit controller, a double throw switch, latches for holding said switch in its two positions, an over-the-center spring for throwing said switch, and a vibrating shifter for tripping said latches and for shifting said spring, and means controlled by said switch for automatically and intermittently operating said shifter.

2. In a circuit controller, a double throw switch, an independently mounted, pivoted shifter and cooperating means for effecting the quick throw of said switch at the ends of the movement of said shifter, and a thermostatic device engaging said shifter adjacent its pivot for operating the same.

3. In a circuit controller, a double throw switch comprising an oscillating support, spring contact fingers on said support and cooperating fixed contacts, latches for engaging and holding said support in its two positions, an over-the-center spring for shifting said support, a vibrating shifter for tripping said latches and effecting the operation of the spring, and means controlled by said switch for automatically vibrating said shifter.

4. In a circuit controller, a double throw switch comprising an oscillating support, spring contact fingers on said support and cooperating xed contacts, latching means for holding said support in its two positions, spring means for shifting said support, a vibrating shifter for tripping the latching means and effecting the operation of the spring means, and an electrically heated thermostat for automatically vibrating said shifter.

5. In a circuit controller, a double throw switch comprising an oscillating support, spring contact fingers on said support and cooperating fixed contacts, latching means for holding said support in its two positions, spring means for shifting said support, a pivoted shifter for tripping said latching means and tensioning said spring means, an electrically heated thermostat engaging said shifter adjacent its pivot, and a contact on said support for controlling said thermostat.

6. In a controller, a throw over switch, a shifter for said switch, an electrically heated thermostat for operating said shifter, an electrically driven fan for cooling the thermostat, and contact means operated by the thermostat for alternately energizing the same and said fan.

7. In a circuit controller, a double throw switch, an independently mounted vibrating shifter, spring means actuated by said shifter for throwing said switch, latching means tripped by said shifter at the ends of its movement for holding said switch in its two positions, and an electrically heated thermostat controlled by said switch for automatically and intermittently operating said shifter.

8. In a circuit controller, a pivotally mounted double throw switch, an independently mounted pivoted shifter, a spring operated by said shifter for throwing said switch, latches adapted toI be tripped by said shifter at the ends of its movement for holding said switch in its two positions, and an electrically heated thermostat controlled by said switch for automatically and intermittently vibrating said shifter.

9. In a circuit controller, an oscillating double throw switch, a vibrating shifter, an over-thecenter spring connected to said shifter and said switch for throwing the latter, latching means adapted to be tripped by said shifter for holding said switch in its two positions, and means controlled by said switch for automatically and intermittently vibrating said shifter.

10. In a circuit controller, an oscillating double throw switch, an independently mounted pivoted shifter, latching means and spring means controlled by said shifter for effecting the quick throw of said switch at the ends of the movement of the shifter, and an electrically heated thermostatic device controlled by said switch and engaging said shifter adjacent its pivot for operating the same.

CHARLES YEOMANS. 

